PLATE 2077534 - Caterpillar

Illustration 1 g00740911
Hydraulic System Schematic (1) Outlet line from torque converter (2) Flywheel housing (3) Torque converter (4) Torque converter case (5) Inlet line to torque converter (6) Oil pump (7) Oil filter (8) Transmission hydraulic controls (9) Transmission case (10) Output transfer gear case (11) Oil cooler (12) Relief valve for converter outlet (13) Outlet line from oil cooler (14) Supply line to oil pump (15) Magnetic screenThe hydraulic system has a common reservoir. The reservoir is at the bottom of output transfer gear case (10). The reservoir supplies oil for the operation of the torque converter and the transmission. The reservoir also provides lubrication oil for the different components in the system.Oil is pulled from the reservoir through magnetic screen (15) by oil pump (6). Pump (6) sends pressure oil to oil filter (7). The oil flows through the filter. If restrictions are present in the oil filter, a bypass valve in the filter housing allows the oil to bypass the filter.From filter (7), the oil flows to transmission hydraulic controls (8). The transmission selector and pressure control valve controls the pressure and the flow of oil to the transmission clutches for engagement. The transmission selector and pressure control valve also controls the inlet oil to the torque converter.Inlet oil flows through line (5) for the operation of the torque converter. The inlet pressure valve for the torque converter controls the oil pressure to the converter. Leakage oil from torque converter (3) is used for the lubrication of the internal components.After the components are lubricated, the oil flows to the bottom of torque converter case (4). A passage at the bottom of converter case (4) allows the oil to flow to the bottom of transmission case (9). The transmission case also has a passage at the bottom which allows oil to flow to the main reservoir in case (10) .Outlet oil from the converter flows to relief valve (12) for the converter outlet. Relief valve (12) maintains the pressure inside the converter at a minimum of 415 kPa (60 psi). From the outlet relief valve, the oil flows through line (1) to oil cooler (11) .After flowing through the cooler, the oil with a lower temperature flows through outlet line (13) to the transmission planetary group. This oil is for the lubrication of the transmission.